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OR Playbook
Step 8 · Airway

Intubation

Position, laryngoscopy, passing the tube, confirming placement and securing it.

10 min read

The TL;DR

  • Position first: sniffing position, ear to sternal notch, ramp the obese. Position fixes most "difficult" views.
  • Scissor the mouth open, blade in from the right sweeping the tongue left, lift along the handle axis — don't lever on the teeth.
  • Mac blade sits in the vallecula (indirect epiglottis lift); Miller picks up the epiglottis directly.
  • Confirm with sustained EtCO₂ + bilateral breath sounds + chest rise. EtCO₂ is the gold standard.
  • Tube depth ~21 cm at the lip (women) / ~23 cm (men); reconfirm after any position change.

01Position is 90% of the battle

Before you pick up the blade, fix the position. A good view is made at setup, not rescued during laryngoscopy.

  • Sniffing position: flex the lower neck, extend at the atlanto-occipital joint — this aligns the oral, pharyngeal, and laryngeal axes.
  • Landmark: the external ear (tragus) should be level with the sternal notch, with the face plane parallel to the ceiling.
  • Ramp obese patients (blankets or a ramp under the shoulders/head) until that ear-to-sternum line is achieved.
  • Bed height: patient's forehead at roughly your xiphoid/umbilicus — don't hunch.
✗ Neutral / flatear sits well below the sternal notch — axes don't align✓ Sniffing positionpad / ramptragus level with the sternal notch · line parallel to floorFlex the lower neck, extend at the atlanto-occipital joint. Ramp obese patients until ear ≈ sternum.
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Neutral vs. sniffing: align the tragus with the sternal notch, line parallel to the floor.
Common mistakes
  • Laryngoscoping a flat or under-ramped patient and blaming the anatomy — fix the position first.

02Laryngoscopy technique

Hold the laryngoscope in your LEFT hand (always, regardless of handedness).

  1. Open the mouth with a right-hand scissor maneuver (thumb on lower molars, finger on upper).
  2. Insert the blade at the right corner, advancing while sweeping the tongue to the left into the flange. Keep the tongue out of your view.
  3. Mac (curved): tip into the vallecula, then lift to indirectly flip the epiglottis up. Miller (straight): pass under and directly lift the epiglottis.
  4. Lift along the axis of the handle — up and away toward the far corner of the ceiling. Do NOT lever back on the upper teeth.
  5. Identify the glottis: vocal cords, the triangular opening, arytenoids posteriorly.
  6. Use external laryngeal manipulation (ELM/BURP) on the thyroid cartilage to bring the cords into view if needed.
Cormack–Lehane laryngeal viewIFull glottisIIPosterior cordsIIIEpiglottis onlyIVSoft palate onlyGrade I–II → intubate. Grade III–IV → bougie, optimize position/ELM, or video laryngoscopy.
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Cormack–Lehane grades. I–II → intubate directly; III–IV → bougie, reposition, or video laryngoscopy.
Pearls
  • If the view is poor, optimize before you abandon: reposition the head, ELM, suction, switch to a bougie or video laryngoscope.
  • Watch the tube tip pass BETWEEN the cords with your own eyes — don't just shove and hope.
Common mistakes
  • Levering the blade against the incisors — chipped teeth and still no view.
  • Rocking back to lift instead of lifting along the handle direction.

03Passing and confirming the tube

  1. With the cords in view, pass the ETT from the right corner of the mouth (keep it out of your line of sight to the glottis) and watch the cuff disappear past the cords.
  2. Remove the stylet, advance to depth, inflate the cuff (just to seal — minimal occluding volume, ~5–7 mL; verify pressure if you have a manometer, < 30 cmH₂O).
  3. Confirm placement — in order of reliability:
  4. - Sustained EtCO₂ for several breaths (the gold standard — esophageal placement gives no sustained trace).
  5. - Bilateral breath sounds, absent over the epigastrium.
  6. - Symmetric chest rise, fogging in the tube, maintained SpO₂.
  7. Set depth: ~21 cm at the lip in women, ~23 cm in men (rule of thumb ≈ 3 × tube size). Listen to rule out a right mainstem (absent left-sided breath sounds → pull back).
  8. Secure with tape/tie and connect to the ventilator.
carinacuff — mid-tracheatip ~3–4 cm above carinateeth / lipDepth at the lip♀ Women — ~21 cm♂ Men — ~23 cmRule of thumb: 3 × ETT sizeConfirm: EtCO₂ + bilateral breathsounds + chest rise, then tape.Always reconfirm depth after repositioning the patient.
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Cuff in mid-trachea, tip a few cm above the carina; tape at ~21 cm (women) / ~23 cm (men).
Common mistakes
  • Calling placement on chest rise alone — confirm with sustained EtCO₂ every time.
  • Advancing too deep → right mainstem intubation (left lung not ventilated, hypoxia). Pull back until bilateral.
  • Forgetting to reconfirm depth after repositioning or moving the patient.

04When it's difficult

If you can't intubate, the priority is oxygenation, not the tube — patients die from hypoxia, not from a missed intubation.

  • Can't intubate but CAN ventilate: mask-ventilate, re-optimize (position, ELM, bougie, video), get help, consider an LMA. You have time.
  • Can't intubate, can't ventilate (CICV): call for help immediately → LMA → and proceed down the difficult-airway algorithm to a surgical airway if needed.
  • Limit attempts — repeated tries cause edema and bleeding that make everything worse. Change something between attempts.
Pearls
  • Default to whatever oxygenates — a mask or LMA that ventilates beats a heroic third laryngoscopy attempt.
  • Call for help early — it's a sign of good judgment, not weakness.
In this guide
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Induction — Putting the Patient to Sleep
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Extubation